Apparatus for installing reinforcing in plastic concrete

ABSTRACT

A concrete roadway paving machine is provided with several transversely arranged freely rotatable paddle wheels which oscillate vertically and ride over the mesh or rod reinforcing to depress the same into the plastic concrete to the desired depth. Where lateral positioning of longitudinal rods is required, the paddles or blades are provided with notches or teeth having related angular edges whereby the oscillation progressively shifts the rods to their correct positions.

United States Patent Hudis [54] APPARATUS F OR INSTALLING REINFORCING IN PLASTIC CONCRETE [72] Inventor: Michael I. Hudis, Brookfield, Wis.

[73] Assignee: Rex Chainbelt Inc., Milwaukee, Wis.

[22] Filed: April 13, 1970 [21] Appl. No.: 27,702

[ 51 July25, 1972 3,319,544 5/1967 Heltzel ..94/39 2,389,773 11/1945 Golden... .....94/39 2,596,206 5/l952 Carnes ..94/39 Primary Examiner-Jacob L. Nackenoff Attorne vErnst W. Schultz and Joseph J. Jochman, Jr.

[ 5 7] ABSTRACT 10 Claims, 9 Drawing Figures PATENTEDJuL 25 I872 sum 3 or 5 APPARATUS FOR INSTALLING REINFORCING IN PLASTIC CONCRETE CROSS REFERENCES TO RELATED APPLICATIONS My applications Ser. Nos. 8,222 and 14,547 respectively filed on Feb. 3 and 26, 1970 are entitled Method of and Apparatus for Placing Continuous Reinforcing in Concrete Paving and Show first and second machines for operation in tandem. The second machine in each application comprises a slip-form paver which includes a bar depressor having the configuration of'a paddle wheel.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to apparatus for use in constructing concrete roads and pavements and in particular for depressing the reinforcing into the fresh or plasticvconcrete. This, of course, must be accomplished immediately after the concrete has been laid on the grade and initially spread. Respreading and finishing of the slab surface is completed alter the reinforcing is installed. The reinforcing may be steel mesh having longitudinal rods and transverse bars arranged to form grids and welded to comprise mats. As reinforcing, the ends of adjoining mats are overlapped and their sides are spaced from the center of the slab where it is to be cut and cracked.

The acceptance and use of continuous rod reinforcement for concrete roadways is relatively recent. Reinforcing rods in varying lengths are delivered to the job site in bundles and may be welded end to end to form continuous rods. More commonly, the ends are generously overlapped and tied together with wire.

The tie bars which are required at the center of the slab if it is to be cut and cracked are generally placed over the mats. Where continuous rods are employed, the tie bars are placed below the rods and are depressed by the rods. Alternatively, transverse bars extending the full width of the slab may be placed below the rods and are depressed by the rods to their required position.

2. Description of the Prior Art My US. Pat. No. 3,260,177 shows a preferred apparatus and method of installing reinforcing mesh by depressing it into the fresh concrete with an oscillating motion which is precisely related to the forward travel of the machine.

US. Pat. No. 3,361,043 shows another apparatus for depressing mesh which comprises a series of discs rotatably supported on a single transverse axis by arms which are vibrated but locked in the predetermined position which is to cause the discs to depress the mesh to the desired depth or elevation in the concrete. U.S. Pat. No. 3,319,544 shows transverse mesh depressors carried by a powered conveyor. The lower run of the conveyor is vibrated. Such vibration unavoidably extends to the surface of the concrete and is wholly undesirable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross section of the machine which includes the tamping blades and the required respreading and finishing means.

FIG. 2 is a slightly enlarged front elevation of the machine shown in FIG. I with details of the frame supporting the rod depressing apparatus shown in FIG. 1.

FIG. 3 is a plan view of the machine and said frame and shows the continuous rods entering the concrete.

FIG. 4 is a further enlarged cross section of the frame and one sub-frame and shows the arrangement of the tamping blades and the oscillating mechanism. An overlapped continuous rod and transverse bars are also shown.

FIG. 5 is a front elevation of the center portion of the apparatus with some portions broken away and sectioned.

FIG. 6 is an enlarged view of one end portion of a removable serrated tamping blade as attached to the apparatus.

FIG. 7 is a cross section through the blade shown in FIG. 6 at the attaching bolt.

FIG. 8 shows two blades of another size being cut from a one-quarter inch steel 12 inch wide strip.

FIG. 9 is a diagrammatic forward view of the apparatus showing the oscillating mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the present invention as shown is carried by a concrete finishing machine 11 having powered crawler tracks 12 which operate on the grade G along each side of the concrete slab S. The carriages 13 for tracks 12 are joined by the cross-frame 14, shown in part, which extends over slab S and supports the engine, controls, etc. of the machine.

In operation,machine l1 follows a concrete spreader, not shown, which receives the concrete, places it on the grade and initially spreads the concrete. The spreader, or another machine also preceding machine 11 supports the continuous reinforcing rods R which pass between the upper and lower rolls l7 and 18 carried at the forward end of the arms 19 extending from machine 11. The cross member 20 carries a series of guide rolls 21 which space the rods as required. The transverse bars B are placed on the slab S at spaced intervals and beneath rods R ahead of machine 11. Bars B may be full width reinforcing bars or short tie bars, as shown, which join the two halves of the slab after it is cut and cracked. Bars B are depressed to position in slab S by the rods R as will be described.

After the rods and bars have been depressed, the concrete of slab S is respread by the auger screws 22 and the strike-off 23 of machine 11. Screws 22 and strike-off 23 are carried by cross-frame 14 between the slip-forms 25 which are carried by crawler carriages 13 and define the sides of slab S. l

The left and right frames 28 (as viewed in drawings) comprise front and rear box beams 29a and b and 30a and b which are joined by the short l-beams 31. Frames 28 support the depressing apparatus of the present invention and are pivotally joined by the pivot 32 at the center of machine II. Their opposite ends are supported by carriages 13 and extension 33 of one frame is provided with a screw adjustment 34 which allows the frames to be angularly adjusted to match the crown of grade G and slab S.

Each frame 28 carries two oscillating unitsand each unit comprises a sub-frame and a set of freely rotating tamping blades 37. Each sub-frame comprises two spaced, parallel triangular plates 39 which are rigidly joined by the upper front and lower rear parallel tubes 40 and 41, respectively. Each end of tube 41 is supported by a'bracket 42 which is connected by a bearing 43 to the lower end of a leg 44 extending downward from a rear beam 29b or 30b.

Each end of tube 40 is supported by a bracket 45 which is connected to an eccentric rod 46 by a bearing 47. Rods 46 operate on eccentrics 46a fixed on the shafts 48 which are carried by the bearing blocks 49 supported on the Ibeams 31 of frames 28. The adjoining ends of shafts 48 at the center of machine 11 are connected by a suitable coupling 50. Coupling 50 permits angular and endwise movement of shafts 48 relative to each other when the beams 29a and 30a are pivoted relative to each other.

The hollow, rigid shaft 51 for each set of tamping blades 37 is internally provided at each end with a bearing 52 by which it is mounted on the post 53 carried by the plate 39 of the respective sub-frame. Each shaft 51 as shown includes axially spaced support discs 54 and the mounting bars 55 which are welded to the periphery of the discs and are equally spaced about and parallel to the axis of the shafi.

The blades 37 are removably secured to bars 55 as by the bolts 59 and their lower edges may be plain or serrated as shown to form a series of triangular pockets and teeth 37a having inclined left and right edges 60.

The blades 37 are readily removable for replacement if worn and also so that they may be replaced with other blades having different pocket spacing. FIG. 8 shows the manner in which two such blades may be conveniently flame-cut from a single steel plate.

The vertical oscillation of each unit is provided by the power means 61 shown diagrammatically and which rotates the shafts 48. The power means may be carried by one of frames 28.

The eccentrics 46a operate so that the four sets of tamping blades 37 are oscillated at a frequency in the order of 100 to 300 cycles per minute and with an amplitude in the order of three-quarters of an inch.

Eccentrics 46a are arranged so that the tamping action of the sub-frames and of each rotating assembly is phased as shown in FIG. 9. As such, the two center units are 90 out of phase and the two units on each side of the machine operate in opposite relation, that is, their phases are spaced 180. As shown, the blades 37 at the left are moving oppositely at maximum velocity and the blades at the right are at the limits of their stroke. This arrangement provides a near uniform load on the power means 61 and minimizes the reactive forces which are applied by frames 28 to crawler carriages l3. i The low-frequency oscillation and the "free-wheeling of the several sets of tamping blades is essential to the operation of the apparatus and the method by which the rods R are depressed or tamped to the proper elevation in the slab and without any permanent bending of the rods. By free wheeling it is meant that each circularly arranged series of blades 37 carried bya shaft 51 is free to rotate on the bearings 52 which support the shaft.

The free-wheeling of each set of blades 37 absolutely guarantees that-the blades enter and leave the slab S with a minimum of disturbance of the concrete. Further, where plain blades are used to depress mesh which is discontinuous, the free-wheeling assures that the mesh is not tamped forwardly or rearwardly. The mechanism which must be provided in the prior art to move the depressing bars in timed relation to the forward motion of the machine is, of course, not required. The oscillating motion is also essential to'the action of the teeth between the rods R which is such that if a bar B is in the downward path of such teeth, the oscillating motion of the descending blade when it initially contacts the bar will displace the bar'laterally, that is, either forwardly or rearwardly respecting the travel of the machine. This displacement will be effected always before the descending bar 37 contacts the rods R and before the bar B has been depressed to its required position.

The narrow dimension of plates 39 allows the ends of blades 37 to be closely spaced to reach the required positions of rods R. Brackets 42 and 45 may be angularly adjustable, if

' required, and as such will provide adjustment of both the stroke and the elevation of blades 37.

I claim:

1. Apparatus for installing reinforcing consisting of longitudinal rods by depressing the same into a plastic concrete slab to form a roadway, said apparatus including a frame extending over the slab and having supportmeans allowing the frame to move forwardly over the reinforcing as the latter is positioned near the surface of the slab, an assembly of spaced-apart parallel blades circularly arranged about a transverse axis and disposed so that the lower edge of the lowermost blade reaches to the desired elevation of the rods, bearings supporting said assembly for free rotationabout said axis, and power means carried by said frame and supporting said bearings and operable to lift and lower the bearings and said assembly repititiously and with a fixed stroke as the assembly is rotated about said axis by the concrete with the forward movement of the frame, whereby each blade in succession moves downwardly into the concrete and progressively depresses the reinforcing to the desired position in the slab and withdraws from the concrete.

2. The invention of claim 1 wherein the bearings and assembly are laterally restrained with respect to the frame and the outer edge of each blade is serrated to form teeth and intermediate pockets defining the desired positions of the rods, whereby each downward movement of each lower blade moves the rods bpth downwardly and laterally as required.

The invention of claim 1 wherein the blades are segmented and the frame is jointed at the center of the roadway and adjustable to provide said transverse axis with whatever crown matches that of the roadway.

4. Apparatus for depressing in a fresh concrete slab to form a roadway the required continuous reinforcing consisting of longitudinal rods, said apparatus comprising a frame extending over the slab and having supporting means at each side thereof for moving the frame forwardly over the reinforcing as the latter is positioned at the surface of the slab, a number of transversely extending shafts below said frame, a sub-frame rotatably supporting each shaft for free rotation independent of the other shafts, a series of radially extending blades circularly arranged about and carried by each of said shafts such that the lowermost blades of the several shafts are disposed to reach the desired elevation of the rods in the slab, and means connecting said sub-frames to said frame and including power means to oscillate each sub-frame and the respective shafts and blades as a unit with a vertical component of a fixed length whereby the lower blades of each unit are operative to tamp the corresponding rods in a positive manner to the desired position in the slab as the blades-are rotated about their axis by the forward movement of the frame.

5. The invention of claim 4 wherein the periphery of each tamping blade is serrated to provide triangular teeth and intermediate pockets having upper corners defining the desired positions of the rods, whereby the vertical oscillation of the teeth of the lower blades engage and move the rods both downwardly and laterally as required.

6. The invention of claim 5 wherein the tamping blades are removably secured to the respective shafts and are replaceable if worn or with blades having pockets of difi'erent later spacing if required.

7. The invention of claim 4 wherein the frame is jointed intermediate two sub-frames and is adjustable so that the profile of the rods is provided with whatever crown matches that of the roadway.

8. The apparatus of claim' 4 which includes four tamping units and the power means is arranged to oscillate the two units at each side in opposite phase and the units adjacent the center at out of phase.

9. The invention of claim 4 wherein each sub-frame comprises two spaced rigid vertical plates and rigid interconnecting means, the adjacent plates of adjoining sub-frames being closely spaced and the nominal lateral dimensions of the plates allowing the ends of the blades of the respective units to be closely spaced and to reach the required positions of the rods.

10. The invention of claim 4 wherein the power means to oscillate each unit comprises a power-driven cross-shaft carried by the frame, eccentrics fixed on the cross-shaft and rods connecting the eccentrics and the sub-frames. 

1. Apparatus for installing reinforcing consisting of longitudinal rods by depressing the same into a plastic concrete slab to form a roadway, said apparatus including a frame extending over the slab and having support means allowing the frame to move foRwardly over the reinforcing as the latter is positioned near the surface of the slab, an assembly of spacedapart parallel blades circularly arranged about a transverse axis and disposed so that the lower edge of the lowermost blade reaches to the desired elevation of the rods, bearings supporting said assembly for free rotation about said axis, and power means carried by said frame and supporting said bearings and operable to lift and lower the bearings and said assembly repititiously and with a fixed stroke as the assembly is rotated about said axis by the concrete with the forward movement of the frame, whereby each blade in succession moves downwardly into the concrete and progressively depresses the reinforcing to the desired position in the slab and withdraws from the concrete.
 2. The invention of claim 1 wherein the bearings and assembly are laterally restrained with respect to the frame and the outer edge of each blade is serrated to form teeth and intermediate pockets defining the desired positions of the rods, whereby each downward movement of each lower blade moves the rods both downwardly and laterally as required.
 3. The invention of claim 1 wherein the blades are segmented and the frame is jointed at the center of the roadway and adjustable to provide said transverse axis with whatever crown matches that of the roadway.
 4. Apparatus for depressing in a fresh concrete slab to form a roadway the required continuous reinforcing consisting of longitudinal rods, said apparatus comprising a frame extending over the slab and having supporting means at each side thereof for moving the frame forwardly over the reinforcing as the latter is positioned at the surface of the slab, a number of transversely extending shafts below said frame, a sub-frame rotatably supporting each shaft for free rotation independent of the other shafts, a series of radially extending blades circularly arranged about and carried by each of said shafts such that the lowermost blades of the several shafts are disposed to reach the desired elevation of the rods in the slab, and means connecting said sub-frames to said frame and including power means to oscillate each sub-frame and the respective shafts and blades as a unit with a vertical component of a fixed length whereby the lower blades of each unit are operative to tamp the corresponding rods in a positive manner to the desired position in the slab as the blades are rotated about their axis by the forward movement of the frame.
 5. The invention of claim 4 wherein the periphery of each tamping blade is serrated to provide triangular teeth and intermediate pockets having upper corners defining the desired positions of the rods, whereby the vertical oscillation of the teeth of the lower blades engage and move the rods both downwardly and laterally as required.
 6. The invention of claim 5 wherein the tamping blades are removably secured to the respective shafts and are replaceable if worn or with blades having pockets of different lateral spacing if required.
 7. The invention of claim 4 wherein the frame is jointed intermediate two sub-frames and is adjustable so that the profile of the rods is provided with whatever crown matches that of the roadway.
 8. The apparatus of claim 4 which includes four tamping units and the power means is arranged to oscillate the two units at each side in opposite phase and the units adjacent the center at 90* out of phase.
 9. The invention of claim 4 wherein each sub-frame comprises two spaced rigid vertical plates and rigid interconnecting means, the adjacent plates of adjoining sub-frames being closely spaced and the nominal lateral dimensions of the plates allowing the ends of the blades of the respective units to be closely spaced and to reach the required positions of the rods.
 10. The invention of claim 4 wherein the power means to oscillate each unit comprises a power-driven cross-shaft carried by the frame, eccentrics fixed on the cross-shaft and rods connectinG the eccentrics and the sub-frames. 